In the modern world, many homes and businesses must take extraordinary steps to prevent criminal entry into the premises. These steps commonly include the installation of security bars or a security grill over windows included in the building. Typically, these security grills are permanently affixed to the building exterior over the windows. For security reasons, measures must be taken to prevent the easy removal of the installed grill, particularly from the outside of the building.
Making the security grill difficult to remove creates a major safety problem in the event of a fire, or other emergency, since there may be no other exit available except through the windows. Besides creating a safety hazard, permanently barred windows may violate building codes, particularly where the bars cover bedroom windows, which typically are the only emergency exits from the bedroom.